On Thursday 29 January 2009, Paragon Corporation wrote: > I'm afraid I agree with Jan on this. Like Brent said you'd want to know > about the assumption being made, but I'd just assume not have warnings and > without warnings things like this where there is no match are just too hard > to debug. And code running in lalala land is not going to be looking at > warnings. > > Say your table had a projection of 4326 once and then later your change it > to 2249 or whatever and had no idea there was code lying around thinking it > was working with 4326. Your code would mysteriously just stop producing > results or odd results. > > I'd rather it just break than do the logically wrong thing. > > -1 > > Thanks, > Regina
I second this as well: -1 on assuming anything about SRID. Any kind of default behavior when it comes to SRID should assume the worst- i.e. different SRIDs. This is one of the only safety checks one has when working with geographic data. Cheers, Dylan > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Jan > Hartmann > Sent: Thursday, January 29, 2009 4:52 PM > To: PostGIS Users Discussion > Subject: Re: [postgis-users] More Semantics: SRID Matching > > I wouldn't do that. My experience is that you'll run into errors that are > very hard to detect when you allow this sort of "default" behavior. > What's wrong whith an extra setsrid or so? > > Jan > > Paul Ramsey wrote: > > I just did this: > > > > aggtest=# select name from tm_world_2 where st_dwithin(the_geom, > > 'POINT(32.4122 -21.2178)', 0.0001); > > ERROR: Operation on two geometries with different SRIDs > > > > And you know what, that seems a bit harsh to me. Given an operation > > where one SRID is known (st_srid(the_geom) == 4326), and the other is > > unknown (-1), can we not simply assume that everything is in the known > > SRID? > > > > Comments? > > > > P > > _______________________________________________ > > postgis-users mailing list > > [email protected] > > http://postgis.refractions.net/mailman/listinfo/postgis-users > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users -- Dylan Beaudette Soil Resource Laboratory http://casoilresource.lawr.ucdavis.edu/ University of California at Davis 530.754.7341 _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
